“And you will count the day after Shabbos…”
The Medrash says that “The mitzvah of the Omer should not be light in your eyes, for the Jews merited Eretz Yisrael because of the Omer.” What is the special significance of the Omer more than any other mitzvah?
The Ramban, at the end of Parshas Bo, explains why we have so many mitzvos which connect us to the exodus from Mitzrayim. Why do we constantly have to remember Mitzrayim? He explains that from the great and open miracles of Mitzrayim, a person can recognize the hidden miracles which surround every aspect of our lives. There is no such thing as nature. Everything is miraculous, albeit hidden within the natural framework.
The mitzvah of the Omer is to strengthen this belief within Klal Yisrael. The first harvest is a time to reflect upon the hidden miracle of parnassah, sustenance. After celebrating the open miracles of Mitzrayim, the Torah tells us immediately to bring the Omer, because we need to take that awakening and inspiration of Pesach and recognize the hidden miracles which the Omer represents. This mitzva is the vehicle to bring the message of Pesach into our every day life.
The place of realizing the world of the hidden miracle was in Eretz Yisrael. A time and place when every man would “sit beneath his grapevine and beneath his fig tree”, and use the physical world as a vehicle to reach Hashem. The lesson of the Omer was relived daily by every Jew in the Land. It was the merit of the Omer which enabled us to live in the Land, for it taught us this lesson which was chiefly felt in the Land.
(based on Afikei Mayim)